Thermal and fluid flow simulation of a compact heat exchanger with micropillar

Resumo

Technological advances in manufacturing processes and materials have enabled the miniaturization of electronic components, which is positive in many ways but also introduces thermal management challenges due to the increased power density of components and reduced surface area for heat dissipation. In this sense, the use of compact heat exchangers presents itself as a possibility for controlling the temperature of these devices, such as those based on micropillars and microchannels. This study is based on the numerical simulation of a compact heat exchanger of square micropillars with 0.3 mm width and height and 0.2 mm inter-fin spacing, with different arrangement configurations. Deionized water is used as the working fluid for the single-phase flow regime under different mass velocities (442 to 1096 kg/m²s) and input heat powers (9 to 15 W). The modeling was implemented in the Ansys Fluent software, and the results obtained were validated and compared with experimental data, where data adherence was verified. Moreover, the numerical results were compared with another numerical reference case based on a plain surface without micropillars. Considering the thermo-hydraulic behavior through the Thermal Performance Index (TPI), the staggered arrangement presents the best performance, even though its pressure drop is greater than in the aligned arrangement. Regardless of the micropillar arrangement, a TPI greater than one was found, indicating that micro-pin fin heat sinks can be very effective as a thermal management technique.